2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/44581Treating the Koide equation and another efficient charged-lepton mass formula (having the form of a mass sum rule) as a system of two mathematically independent algebraic equations for three charged-lepton masses, we predict the tauon mass as well as the ratio of electron and muon masses, both consistent with experiment.1+7 pagesHigh Energy Physics - Phenomenologytext